1. Field of the Invention
The present invention relates to a method for detecting combustion timing of an engine that analyzes an engine vibration signal that is measured so as to determine combustion timing of an engine, and a system thereof.
2. Description of Related Art
Unlike a conventional gasoline or diesel engine, in a direct injection compression ignition type of engine such as a homogeneous charge compression ignition (HCCI) engine and a controlled auto ignition (CAI) engine, factors that are related to the combustion are restricted such that an indirect control method is used to control the combustion thereof.
An important factor in the compression ignition engine that indirectly controls combustion timing is to determine how the combustion of the engine is progressing.
As techniques that directly analyze combustion, there are a method of measuring the pressure of the combustion chamber and a method using an ion probe.
In the method measuring the pressure of the combustion chamber, the released heat amount is calculated during combustion to accurately analyze the combustion process.
The method of using an ion probe measures the ion amount that is generated before and after the combustion to analyze the combustion progress of the combustion chamber.
In the above techniques for directly measuring the combustion, the combustion is measured through data that are extracted from sensors that are mounted inside the combustion chamber such that there is a merit of accurately analyzing the combustion progress.
However, when high temperature and high pressure conditions are repeated inside the combustion chamber, in a case that the sensors are directly exposed to the combustion fire, there is a problem that sufficient durability thereof cannot be achieved, and further the sensors are expensive such that it is difficult to apply to a mass produced vehicle in a practical aspect.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.